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Optical Power Budget: How to Calculate a Fiber Link

Calculate a fiber link loss budget before pulling cable: Tx power minus Rx sensitivity, dB/km, connector, splice and splitter values, with worked exam

admin 2026-09-14

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DWDM 50GHz vs 100GHz Channel Spacing on the ITU Grid

ITU-T G.694.1 fixed and flexible DWDM grids: wavelength maths, 50GHz vs 100GHz trade-offs, filtering and OSNR cost, migration and a validation checkli

admin 2026-09-14

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PAM4 vs NRZ: Modulation Behind 100G, 400G and 800G Optics

PAM4 vs NRZ explained for 100G, 400G and 800G optics: bits per symbol, the 9.5 dB SNR penalty, why KP4 FEC is mandatory, TDECQ, DSP and link troublesh

admin 2026-09-09

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DWDM System Components: MUX, EDFA and DEMUX Explained

Learn DWDM building blocks: transponders, MUX/DEMUX and ROADM filters, singlemode fiber, EDFA and Raman amplifiers, ASE and OSNR reach limits.

admin 2026-09-08

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Optical Transceiver Power: Reading Rx/Tx dBm Correctly

Read SFP DOM light levels correctly: Tx and Rx power in dBm, typical ranges for 1G and 10G SR/LR optics, warning vs alarm thresholds and fault pattern

admin 2026-09-07

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SFP Optical Transceiver Troubleshooting: Engineer's Checklist

SFP transceiver troubleshooting checklist: read DOM data, clean end faces, check coding, compare Tx and Rx power on both ends, then isolate the fault.

admin 2026-09-02

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OTDR Testing Basics: Measuring Fiber Links and Locating Faults

Learn OTDR fundamentals: backscatter, key settings (wavelength, pulse width, RI), reading events and dead zones, and a workflow that locates fiber fau

admin 2026-08-30

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